Final answer:
The abandonment of Dougouba was due to the decline and eventual collapse of the Mali Empire, brought on by economic challenges, political instability, invasions, and internal conflicts, which led to famine and water scarcity.
Step-by-step explanation:
The desertion of the city of Dougouba in Mali was caused largely by economic decline and political instability, which triggered a series of other catastrophic events. With the inflow of external challenges such as invasions by neighbors, internal rebellions, and the rise of new powers, the erstwhile robust economy of the Mali Empire suffered. These factors ultimately weakened Mali, making it vulnerable to further collapse. The city's abandonment can be attributed to the aftermath of such turmoil, including pillaging by invaders, approximately a century later in the region, which led to the destruction of infrastructures, such as the filling in of water wells and the burning of fields, causing famine and water scarcity.